Ongoing and planned studies include evaluation of populations exposed to benzene, chlorinated solvents, organochlorines, disinfection byproducts. polycyclic aromatic hydrocarbons, arsenic, formaldehyde, diesel exhaust, coal combustion products, and selected pesticides. On-going case-control studies of stomach, esophagus, brain, bladder, renal cell, thyroid, prostate and breast cancer, NHL, and benzene-induced hematotoxicity and hematologic malignancies and cohort studies of women in China and agricultural workers in the United States are evaluating a range of potential genetic risk factors and their interaction with occupational and environmental exposures. Many of these studies are also collecting tumor samples for future molecular analyses.